Problem: What is the greatest common factor of $10$ and $7$ ? Another way to say this is: $\operatorname{gcf}(10, 7) = {?}$
Explanation: The greatest common factor is the largest number that is a factor of both $10$ and $7$ The factors of $10$ are $1$ $2$ $5$ , and $10$ The factors of $7$ are $1$ and $7$ Thus, the greatest common factor of $10$ and $7$ is $1$. $\operatorname{gcf}(10, 7) = 1$